Diagram of a Reverse Circulation Drilling system.
Reverse Circulation Drilling
There are two types of Reverse Circulation Drilling available today. Both of these methods use the exact same dual wall drill pipe. The only difference is the hammer that attaches to the pipe.
The two types of Reverse Circulation Drilling are:
This is the newer of the two methods. This method uses a special Center Sample Hammer with a hollow center that allows the sample into the dual wall drill pipe right at the face of the drill bit.
This is the original RC with a conventional Down Hole Hammer and a 'Interchange' (adaptor just above the hammer with a vertical slot to let the sample into the center of the Dual wall drill pipe.
The advantage of the Center Sample Hammer is the sample goes immediatelly into the drill pipe without having to travel up the side of the conventional hammer and into the interchange (approx 4 feet).
Midnight Sun Drilling utilizes the Center Sample System on all of our mineral exploration programs. (in the 4" - 6" sizes) The center sample hammer is available up to a 16" hole.